Journal of Conchology 42 (3), February 2016

ISSN 2755-3531

 

Plagiodontes parodizi, a new species from Argentina (Gastropoda: Odontostomidae)

J. Pizá & N.J. Cazzaniga

Abstract. Plagiodontes parodizi sp. nov. inhabits Sierra de Guasayán, a restricted biogeographical area in Argentina and presents as diagnostic characters an elongate-ovate medium-large shell, a reticulated teleoconch sculpture, and a long convoluted free portion of the FPSC forming two circumvolutions. Previously assigned to P. brackebuschii (Doering 1877), the shells from Guasayán differ from the type specimens of Plagiodontes brackebuschii in shell shape, teleoconch sculpture and suture characteristics.

Key words. Stylommatophora, Orthalicoidea, taxonomy, Plagiodontes brackebuschii, internal anatomy

New taxon. Plagiodontes parodizi Pizá & Cazzaniga, 2016

Date of publication. February 2016

 

First reports of two terrestrial slugs (Gastropoda: Eupulmonata) from southern Africa

Ben Rowson, David G. Herbert & E. Fay Robertson

Abstract. Two large slug species are reported from southern Africa for the first time. Arion flagellus Collinge, 1893 (Arionidae) was found in a pine plantation in KwaZulu-Natal, South Africa in 2014. It originates in western Europe, and may spread via commercial forestry to climatically similar areas. Polytoxon robustum (Simroth, 1896) (Urocyclidae) belongs to the less well-studied tropical African slug fauna. It has been established in Harare, Zimbabwe since the 1990s but was identified only in 2015. It may have been introduced from Central or East Africa, where it has broad habitat and climate preferences.

Key words. Introduced, non-native, pests, plantations, Mollusca, Arionidae, Urocyclidae

Date of publication. February 2016

 

Rediscovery and a redescription of Vermetum festinans from La Palma, Canary Islands (Gastropoda Pulmonata: Gastrodontidae)

D.T. Holyoak, G.A. Holyoak, J. Santana, J.M. Castro, M.R. Alonso & M. Ibáñez

Abstract. Vermetum festinans was hitherto known only from a few shells collected on La Palma. It is the type species of Vermetum, which has sometimes been classified in the Pristilomatidae. The recent allocation of a second species newly discovered on Gran Canaria, V. tamadabaensis, to the same genus was based only on close similarity of its shells to those of V. festinans. The genus was transferred to the Gastrodontidae from the Pristilomatidae on the basis of characters of the genital anatomy shown by V. tamadabaensis. Efforts to refind living V. festinans were successful in 2015, allowing the redescription here of its shells and habitat and the first studies of its genital anatomy. It closely resembles V. tamadabaensis anatomically, sharing the presence of a sarcobelum and three “bridges” joining parts of the distal genitalia, differing only in details. The new data therefore confirm that the genus Vermetum should be transferred to the Gastrodontidae and that two species should be recognised.

Key words. Canary Islands, land-snails, endemic, generic taxonomy, genital anatomy

Date of publication. February 2016

 

Opisthobranchiate Mollusca from Ghana: Tergipedidae, with a checklist and a review of the ecology and diversity of the Aeolidioidea

Malcolm Edmunds

Abstract Descriptions are given of seven species of Tergipedidae from Ghana of which three are new, Cuthona ghana n. sp., Cuthona kpone n. sp. and Cuthona species A, while a fourth is a very immature unnamed species of Tergipedidae. Cuthona perca, Cuthona ghana n. sp., and Tenellia adspersa are all part of the fouling community in harbours and on boats while Cuthona kpone n. sp., Cuthona species A, Catriona tema and the unnamed tergipedid all occur on shallow reefs. Thirty-two species of aeolid nudibranchs have been recorded from Ghana, the most biodiverse site being the 10m deep offshore reef. It is estimated that a more intensive study might have yielded a few more species. Thirteen of the 32 species are currently only known from Ghana, probably because west African nudibranchs are so poorly known. Others also occur elsewhere in the Gulf of Guinea, Angola, the Azores, Canaries, Madeira, the Mediterranean and even northern Europe. There are 6 amphiatlantic species and 3 recorded from the Indo-Pacific, these latter probably being transported by boats.

Key words. Tergipedidae, Cuthona, Catriona, Tenellia, biodiversity

New taxa. Cuthona ghana Edmunds, 2016; Cuthona kpone Edmunds, 2016

Date of publication. February 2016

 

A new species of Lodderena (Trochoidea, Skeneidae) from Guam Islands (Pacific Ocean)

Alexei Chernyshev, Emilio Rolán & Federico Rubio

Abstract. A species belonging to the genus Lodderena was found in Guam Island. After comparing it with other species of similar morphology, it was found to be new to science and is described here.

Key words. Skeneidae, Lodderena, new species, Guam Islands

New taxon. Lodderena vladimiri Chernyshev, Rolán & Rubio, 2016

Date of publication. February 2016

 

Taxonomic position of Helicella (Jacosta) syrensis carinatoglobosa Haas, 1934

Marco T. Neiber & Kevin A. Schlegel

Abstract. The taxonomic position of the insufficiently known nominal taxon Helicella (Jacosta) syrensis carinatoglobosa Haas, 1934 is discussed on the basis of genital morphology. Our results show that the taxon is a separate species that ought to be classified in the genus Xerocrassa Monterosato, 1892 and not in the genus Trochoidea Brown, 1827 as proposed in several recent publications. Xerocrassa carinatoglobosa is a narrow-range endemic restricted to the Akrotiri Peninsula in southern Cyprus.

Key words. Xerocrassa, Trochoidea, Cyprus, systematics, genital system

Date of publication. February 2016

 

Revision of Rhysotina (Gastropoda: Urocyclidae) land-snails endemic to the West African island of São Tomé

David T. Holyoak & Geraldine A. Holyoak

Abstract. Rhysotina (Urocyclidae) is a small genus endemic to the oceanic island of São Tomé in the Gulf of Guinea, off tropical west Africa. It is revised based on shell and spirit specimens collected by the authors in 2013. Two species have been recognised for many years, R. hepatizon (Gould 1845) and R. welwitschi (Morelet 1866). The second of these is shown to have been confused with a third species that is newly described here; they differ in several shell characters and their altitudinal ranges. The genital anatomy is redescribed and figured for all three species, which have similar genitalia despite their distinctive shells. The “unique character” of “a very peculiar structure” of the genital atrium that contributed to naming of the family Rhysotinidae Schileyko 2002 was most likely from a snail that was atypical or distorted in preservation. Nevertheless, because the genus has other peculiarities and the small amount of published molecular data suggest it forms a sister-group to other sampled Urocyclidae, it is tentatively separated from them here as the Subfamily Rhysotininae.

Key words. Rhysotina, Rhysotinidae, Urocyclidae, São Tomé, oceanic island, endemics, new species, genital anatomy, shells

New taxon. Rhysotina sublaevis Holyoak & Holyoak, 2016

Date of publication. February 2016

 

A new species of endoparasitic mollusc from the Arctic (Gastropoda: Eulimidae)

Ivan O. Nekhaev

Abstract. The shell-less gastropod Entocolax olgae sp. n., an endoparasite of the holothurian Myriotrochus rinkii Steenstrup, 1851, is described from two localities in the eastern part of the Laptev Sea. Entocolax olgae has a deep longitudinal fold in the intestine, a unique feature differentiating it from all other known members of the genus. There are also some differences in the reproductive system and siphon structure. Taxonomically significant morphological features of other Entocolax Voigt, 1888 species known from Eurasian seas are also reviewed.

Key words. Eulimidae, Entocolax, Arctic, parasite, new species

New taxon. Entocolax olgae Nekhaev, 2016

Date of publication. February 2016

 

Habitat structure effects on the distribution and abundance of the rare snail Vertigo moulinsiana (Dupuy, 1849)

Anna M. Lipińska & Adam M. Ćmiel

Abstract. Vertigo moulinsiana is a rare, small, land snail species, living in wet areas with high pH and calcium content. This paper presents the results of analysis of microclimatic and microhabitat variables, and their effect on the occurrence and abundance of this species. The research was carried out at one of the few sites for the species in Poland: in wetlands located in the valley of the Nida river. Vertigo moulinsiana in the studied area selects microhabitats with a high level of groundwater, covered with vegetation of reed mannagrass: “carex and glyceria” and “glyceria”, and a thick layer of litter. The vegetation type significantly depends on the groundwater level and significantly affects the soil content of organic matter and the vegetation height. 

Key words. Vertigo moulinsiana, Desmoulin’s whorl snail, distribution and abundance, microhabitat, microclimate, habitat structure, Polish wetlands

Date of publication. February 2016

 

The cryptogenic river snail Viviparus viviparus expands its range in Ireland: case of a re-introduction?

Dan Minchin

Abstract. The river snail Viviparus viviparus was known in Ireland from deposits in the Shannon and Barrow river catchments almost a century ago. It was only recently, since 1995, that living populations were found in the upper Shannon. Since these records further snails were found at separate localities along the length of the Shannon and Erne catchments and from near Lough Neagh. It would appear that this snail might be a reintroduction to Ireland. The modes of transmission that might have been involved in its arrival are discussed.

Key words. River snail, Shannon, Erne, introduction, expansion

Date of publication. February 2016

 

A sclerochronological analysis on the Mediterranean bivalve Ostrea edulis (Linnaeus, 1758): a quick age determination method

Mauro Pietro Negri & Cesare Corselli

Abstract Valves of the ostreid bivalve Ostrea edulis (Linnaeus, 1758) were analyzed by visual sclerochronology based on umbonal ridges and internal growth lines, along with the calcitic chalky lenses deposited below the adductor muscle scars. The lenses are herein proposed for the first time as a tool for a quick age determination. The analysis revealed ages of 5 to 7.5 years, consistent with shells’ dimensions. A Von Bertalanffy growth curve, markedly different from published analogous ones, showed that shell height alone is not a valid proxy for age determination. The adopted sclerochronological method is advised for age assessment of oyster settlement on human artifacts on the seafloor.

Key words. Sclerochronology, Ostrea edulis, chalky lenses, Von Bertalanffy

Date of publication. February 2016

 

New species of Oxychona (Bulimulidae) from Michelin Ecological Reserve (Bahia state, northeastern Brazil)

Rodolfo Porto, José Raimundo da Rocha Filho, Rodrigo Johnsson & Elizabeth Neves

Abstract. A new species of Oxychona was found during excursions to the Michelin Ecological Reserve (13°S), southern Bahia state (northeastern Brazil), which comprises an Atlantic Rainforest Conservation Unit. Living snails and empty shells were collected from ground litter accumulations and kept in an artificial environment supplied with local water and sediment, feeding on leaves of almond tree (Terminalia catappa L.). The new species is described and compared with others from adjacent areas of Brazil between 13°S and 15°S including O. bifasciata, O. currani and O. maculata. Oxychona n. sp. is likely to be endemic to Bahia state, thus supporting the biodiversity and rates of endemism of pulmonate molluscs to the Tropical Atlantic Rainforest in Southern America.

Key words. Bulimulidae, terrestrial gastropod, taxonomy, neotropical region

New taxon. Oxychona michelinae Porto, da Rocha, Johnsson & Neves, 2016

Date of publication. February 2016

 

The Abbottella moreletiana complex in Hispaniola: distributional notes, a new species, and the recognition of a new subfamily (Annulariidae: Abbottellinae)

G. Thomas Watters

Abstract. The Hispaniolan Abbottella morelatiana complex is reviewed. A new species, Abbottella crataegus sp. nov., is described. Based on phylogenetic evidence, shell morphology, and radular characteristics, Abbottella and its associated genera Leiabbottella, Lagopoma, and Rolleia are placed in a new subfamily of the Annulariidae, the Abbottellinae.

Key words. Hispaniola, Gastropoda, Annulariidae, Annulariinae, Abbottella crataegus sp. nov.

New taxa. Abbottella crataegus Watters, 2016; Abbottellinae

Date of publication. February 2016

 

First record of the predatory semi-slug Daudebardia rufa (draparnaud, 1805) from the UK (Eupulmonata: Daudebardiidae) [Short Communication]

Christian Owen, Ben Rowson & Karen Wilkinson

Date of publication. February 2016

 

Another wave of invasion? First record of the true Sicilian Slug Deroceras panormitanum sensu stricto from Ireland, and another from Wales (Eupulmonata: Agriolimacidae) [Short Communication]

Ben Rowson, Roy Anderson, Simon Allen, Dan Forman, Carolyn Greig & Nor Azlina Abdul Aziz

Date of publication. February 2016

 

Book review: Conus of the Southeastern United States and Caribbean by Alan J. Kohn. 2014

Harriet Wood

Date of publication. February 2016